I need a beach geologist!

[Annie M.]

Just wondering if anyone can provide me with some information about a sedimentary layer I found at the beach the other day.

The shore at this spot is primarily sandstone that is packed with shell fossils (huge abalone, snail spirals, clams, strange leaves) so I assume that at one time this was the sea bed... this fossil layer is about 20 feet thick and forms a cliff above sea level. The layer that I am interested in is below the sandstone and appears as a black line in the strata... in a few small exposed areas in the intertidal zone this layer appears to be pure carbon (not shale)... jet black with a 'alligator texture to the surface.. I chipped a piece out and it is extremely light. I think it is charcoal... it will make a mark on a piece of paper... it also appears to have a very tight 'grain' when I look at it under a magnifying glass.

I am on the west coast of Vancouver Island and I am very curious about the origin of this 'charcoal' layer and what it actually 'is'. Any insight is appreciated.

Thanks... Annie

[redrockcoulee]

There is a web site that I cannot think of its name, but it is the BC government and there are geological maps on it. But the best would be to contact the geology or geography departments at U of Vic and if you can give the precise location they will be able to tell you the actual formation name so you will find out not only the type of rock but the age of it as well

[Annie M.]

Thanks redrock... long weekend... lights out at U vic.

I never give out the exact location of anything I find ever!! Down the coast at Muir Creek the fossil cliffs have been chewed to bits by the people with their sharp shiny hammers.

I never revealed the location of the petroglyph I found either... although the government does keep a 'secret list' of significant anthropological sites that will never be revealed to the public... mine wasn't on it and will never be. Sounds paranoid I know but it is amazing what some people will try to drag home from the beach.

[Ole Tjugen]

That sounds like coal - at least to this petroleum geologist.

[Bryan Lemasters]

Annie,

A local government geological survey office would be able to answer you question. Take a sample of it to show them. This vein may be very localized and not show up on a map, though. While it could be the carboniferous remains of a small bog later covered by other strata, it sounds more like it could also be the remains of a tar pit or oil seep. In Ritchie County, West Virginia (a long way from Vancouver Island, I know) there was an oil seep that woked it's way up through fissures in the surrounding rock strata along an anticline and over the eons solidified into what appeared to be coal (and was mined as such). However, when heated or burned, this "coal" would melt and drip. Try breaking off a piece and lighting it. Will it burn? Does it appear to soften or melt? Sounds interesting. Good luck.

Bryan

[J D Clark]

My wife, a geologist who got her doctorate in sedimentary geology, also supports Ole's answer that it's coal.

John Clark
www.johndclark.com

[David Vickery]

http://www.llbc.leg.bc.ca/public/Pub...0-bickford.pdf

This is a link to an assessment of the coal on Vancouver Island. Although they mainly address the eastern side of the island--I didn't read along far enough to see if they mention the western side of the island--it isn't unlikely that the same formations would extend across the island.

[Annie M.]

It glows! I can get it to glow red by a candle flame... looks like it is coal... smells organic when it smoulders... wonder if I can grind this down and do some kind of carbon printing with it... now if only I could find a vein of platinum to print with!

Thanks everyone... a

[Ole Tjugen]

"Coal" is a very wide classification, and in "proper" classification we use a lot of different terms for various different properties.

Finding thin layers of coal in sandstones is not uncommon, and in oil drilling it is one of the most common "problem zones".

[Ole Tjugen]

By the way: http://web.viu.ca/earle/mal-cut/geol...ver-island.ppt is a good summary.

Just detailed enough that I can guess where your beach is.